Method, structure, and composition for filling wide cracks and joints in pavement surfaces

ABSTRACT

A method, structure, and composition for repairing wide and/or deep cracks, joints, and other gaps in pavement surfaces using one or a series of layers of a compressible aggregate of uniform size, with each layer of the compressible aggregate having a binder applied thereto which flows downwardly into and binds all or an upper portion of the compressible aggregate.

RELATED CASE

This application claims the benefit of U.S. Provisional Patent Application No. 63/345,589 filed May 25, 2022 and incorporates said provisional application herein by reference in its entirety as if fully set forth at this point.

FIELD OF THE INVENTION

The present invention relates to non-asphalt-based and asphalt-based methods, structures, and compositions for filling and repairing wide cracks, wide joints, and other wide, and/or deep, gaps in concrete or asphalt roads, streets, highways, sidewalks, and other pavement surfaces.

BACKGROUND OF THE INVENTION

In the road construction and maintenance industry, there is often a need to fill large joints or cracks in pavement structures to provide a smoother ride for drivers, and to prevent an excessive ingress of water into the pavement. In some circumstances, defects are purposely introduced into the pavement structure to allow for placement of utility lines, in an operation commonly referred to as “trenching”.

Relatively narrow cracks and joints (those less than about 0.75 inches wide) will normally be repaired using a typical asphalt-based, hot-applied crack and joint sealant. For marginally wider cracks, “backer rods” or “backer boards” formed of paper, plastic, or metal are often inserted into the crack before the sealant is applied. The backer rods or backer boards fill much of the volume of the crack or joint and thereby reduce the amount of the sealant material required for the repair.

However, for larger joints and cracks which are significantly greater than 1 inch in width, other approaches are necessary. When applied in wide cracks or joints in pavement substrates, a typical crack and joint sealant, or a typical mastic filler, will flow into the crack or joint within a relatively short period of time, and therefore will not provide a permanent repair.

Consequently, for asphalt or “blacktop” pavements, more robust hot asphalt cement mixes, or hot mix patches, comprising asphalt binders having solid aggregate materials therein, have been used to provide more permanent repairs, similar to filling potholes. However, the inclusion of incompressible solid aggregate materials in these hot mix asphalt compositions greatly reduces their flexibility, which in turn lowers the ability of the asphalt mix compositions to accommodate joint and crack movements which occur in pavement surfaces as a result, e.g., of changes in the ambient temperature.

Moreover, while the loss in flexibility caused by the inclusion of an incompressible aggregate material in a hot asphalt mix detracts from the effectiveness and durability of the composition for filling and sealing large cracks and joints in asphalt pavement surfaces, this loss of compressibility and flexibility renders hot asphalt mix compositions essentially unacceptable for filling and sealing wide cracks and joints in Portland cement concrete pavement surfaces. When the ambient temperature changes significantly, cracks and joints in cement concrete pavements can open and close, i.e., change width, to such a degree that the use of incompressible aggregate materials in the cracks and joints can cause buckling, additional cracking, or heaving of the pavement structure. In addition, because of the color contrast between the asphalt material and the concrete pavement, the use of an asphaltic sealant to repair a crack or joint in a concrete pavement surface is unsightly.

Consequently, a need exists for an improved method, construction, and composition for filling and repairing wide cracks and joints in cement concrete pavement surfaces, as well as in asphalt pavements, wherein the repair (i) is sufficiently flexible to accommodate the opening, closing, or other movement of cracks and joints in the pavement surface produced by changes in weather conditions; (ii) is long lasting and will maintain adhesion for a significantly extended period of time; and (iii) can be formulated to match, or at least provide significantly less color contrast with the respect to, the gray color of Portland cement concrete.

One form of road construction which has been in use since about 1820 is known as a macadam. A macadam pavement surface generally comprises (a) successive layers of a compacted, evenly sized, crushed stone aggregate material and (b) an asphalt binder material which is applied to the top of each successive layer of the compacted stone. Because of the even size of the individual pieces of the crushed stone, voids are formed between the pieces within each layer of the compacted stone which allow the binder material flow into each layer of the compacted stone to fill the void spaces and bind the aggregate material together.

The macadam technique for constructing roads has not been used in the art for filling or repairing cracks or joints in existing pavement surfaces. Moreover, the nature and amount of the incompressible aggregate material required for building up the multiple layers of a macadam pavement surface would render the macadam construction technique entirely unsuitable for filling and repairing wide cracks or joints in existing concrete pavement surfaces, and in existing asphalt pavement surfaces as well.

SUMMARY OF THE INVENTION

The present invention provides a method, a structure, and a composition for filling wide and/or deep gaps, such as wide cracks and wide joints, in pavement surfaces. The inventive method, structure, and composition satisfy the needs and alleviate the problems discussed above. The inventive method, structure, and composition are well suited for use in repairing wide and/or deep gaps in both cement concrete substrates and asphalt substrates. The repair provided by the inventive method, structure, and composition (a) is sufficiently flexible, even when used in cement concrete pavements, to accommodate the opening and closing of cracks and joints caused by significant changes in atmospheric temperature, (b) is well suited for repairing gaps in pavements produced by trenching operations, (c) is long lasting, (d) provides strong adhesion over time, and (d) can be formulated to match the color of Portland cement concrete and other pavements.

In one aspect, there is provided a method of filling a gap in a pavement surface which preferably comprises the steps of: (a) forming a layer of a compressible aggregate in the gap in the pavement surface, the layer of the compressible aggregate being a layer of compressible fragments of uniform size wherein the compressible fragments will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh screen and (b) applying a binder on a top of the layer of the compressible aggregate which flows downwardly into voids in the layer of the compressible aggregate. The binder will preferably be a non-asphaltic binder, an asphaltic binder, or a combination thereof.

In another aspect, this method can optionally further comprise the steps, after step (b), of: (c) forming, in the gap in the pavement surface on the layer of the compressible aggregate formed in step (a), a second layer of a compressible aggregate which is the same as or different from the compressible aggregate used in step (a), the second layer of the compressible aggregate formed in step (c) being a layer of compressible fragments of uniform size which will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh screen and (d) applying a binder on a top of the second layer of the compressible aggregate formed in step (c) which flows downwardly into voids in the second layer of the compressible aggregate formed in step (c). The binder used in step (d) can be an asphaltic binder, a non-asphaltic, or a combination thereof and can be the same as or different from the binder used in step (b).

In another aspect, instead of using steps (c) and (d) as just described, the method can optionally further comprise, for example, the binder being applied in step (b) in an amount which flows into and binds only an upper portion of the layer of the compressible aggregate formed in step (a) and leaves a lower portion of the layer of the compressible aggregate below the upper portion unbound. The depth of the upper portion of the layer of the compressible aggregate will preferably be less than the depth of the lower portion of the layer of the compressible aggregate.

In another aspect, there is provided a method of filling a gap in a pavement surface which preferably comprises: (a) sequentially constructing in the gap in the pavement surface a series of bound aggregate layers; (b) each of the bound aggregate layers being constructed of a layer of a compressible aggregate and a binder which is applied on top of the layer of the compressible aggregate and flows into voids in the layer of the compressible aggregate and binds the layer of the compressible aggregate; and (c) the layer of the compressible aggregate of each of the bound aggregate layers being a layer of compressible fragments of uniform size wherein the compressible fragments will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh screen. The binder of each of the bound aggregate layers can be an asphaltic binder, a non-asphaltic binder, or a combination thereof.

In another aspect, there is provided a method of filling a wide gap (e.g., a wide crack or a wide joint) in a pavement surface wherein the wide gap has a width of greater than ¾ inch and more typically has a width of at least about 1 inch, or at least 1.5 inches, or at least about 2 inches. The method preferably comprises the steps of: (a) forming a first layer of compressible aggregate in the gap, the first layer of compressible aggregate being a layer of compressible fragments in a size range which will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh (standard U.S. mesh) screen; (b) applying a binder on top of the first layer of compressible aggregate so that at least a portion of the binder applied on top of the first layer of compressible aggregate in step (b) flows into the voids in the first layer of compressible aggregate to bind the first layer of compressible aggregate together, the binder applied on top of the first layer of compressible aggregate in step (b) being a non-asphalt-based and/or or an asphalt-based binder; (c) forming a second layer of compressible aggregate in the gap, the second layer of compressible aggregate being a layer of compressible fragments in a size range which will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh (standard U.S. mesh) screen; and (d) applying a binder on top of the second layer of compressible aggregate so that at least a portion of the binder applied on top of the second layer of compressible aggregate in step (d) flows into the voids in the second layer of compressible aggregate to bind the second layer of compressible aggregate together, the binder applied on top of the second layer of compressible aggregate in step (d) being a non-asphalt-based and/or an asphalt-based binder, wherein the compressible fragments of step (c) are identical to or different from the compressible fragments of step (a), the size range of step (c) is identical to or different from the size range of step (a), and the binder of step (d) is identical to or different from the binder of step (b).

In another aspect, for a shallow crack, joint, or other gap in a pavement surface, the gap can be filled using steps (a) and (b) of the preceding paragraph without proceeding to steps (c) and (d).

In another aspect, there is provided a method of filling a wide gap in a pavement surface wherein the gap has a width of greater than ¾ inch or more typically at least 1 inch, or at least 1.5 inches, or at least about 2 inches and the method preferably comprises sequentially constructing in the gap a series of bound aggregate layers until the gap is filled, each of the bound aggregate layers being constructed of a layer of compacted compressible aggregate and a binder which is applied on top of the layer of compacted compressible aggregate in an amount such that at least a portion of the binder flows into the voids in the layer of compacted compressible aggregate, the layer of compacted compressible aggregate of each of the bound aggregate layers being a layer of compressible fragments in a size range which will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh (standard U.S. mesh) screen, the binder of each of the bound aggregate layers being a non-asphalt-based and/or an asphalt-based binder, the compressible fragments used in the layer of compacted compressible aggregate of each one of the bound aggregate layers being identical to or different from the compressible fragments used in the layer of compacted compressible aggregate of at least one other of the bound aggregate layers, the size range of the compressible fragments used in the layer of compacted compressible aggregate of each one of the bound aggregate layers being identical to or different from the size range of the compressible fragments used in the layer of compacted compressible aggregate of at least one other of the bound aggregate layers, and the binder used in each one of the bound aggregate layers being identical to or different from the binder used in at least one other of the bound aggregate layers.

In another aspect, for a shallow crack, joint, or other gap in a pavement surface, the gap can be filled using only one bound aggregate layer of the type described in the previous paragraph.

In another aspect, there is provided a method of filling a deep gap in a pavement surface wherein the gap has (i) a depth of at least 5.5 inches or more typically at least 6 inches or at least 6.5 inches, or at least 7 inches, or at least 7.5 inches, or at least 8 inches and (ii) a width of at least 1 inch or more typically at least 2 inches. The method preferably comprises the steps of: (a) forming a single layer of a compressible aggregate in the deep gap, the single layer of the compressible aggregate being a layer of compressible fragments in a size range which will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh (standard U.S. mesh) screen; and (b) applying an amount of a binder on top of the single layer of the compressible aggregate so that at least a portion of the binder applied on top of the single layer of the compressible aggregate flows into the voids in only an upper portion of the single layer the of compressible aggregate to bind the upper portion of the single layer of the compressible aggregate together and to leave a lower portion of the single layer of the compressible aggregate unbound. The binder applied on top of the single layer of the compressible aggregate in step (b) can be a non-asphaltic binder, an asphaltic binder, or a combination thereof.

In another aspect, in the method of the preceding paragraph, the depth of the bound upper portion of the single layer of the compressible aggregate will preferably be equal to or less than the depth of the unbound lower portion of the single layer of the compressible aggregate and will more preferably be less than the depth of the unbound lower portion of the single layer of the compressible aggregate.

Further aspects, features, and advantages of the present invention will be apparent to those of ordinary skill in the art upon examining the accompanying drawings and reading the following Detailed Description of the Preferred Embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a first embodiment of the inventive method and structure for filling a wide gap in a pavement surface.

FIG. 2 schematically illustrates a second embodiment of the inventive method and structure for filling a deep gap in a pavement surface.

FIG. 3 illustrates the result of a test wherein a compacted layer of an incompressible, crushed rock aggregate material of uniform size was placed in a transparent polyethylene terephthalate PET tube. FIG. 3 also shows the flow into the void spaces of the uniform rock aggregate of a hot non-asphalt-based binder which was applied to the top of the aggregate layer.

FIG. 4 illustrates the result of a test wherein a compacted layer of a non-uniform, incompressible, crushed rock aggregate was placed in a PET tube. FIG. 4 , also shows the reduced void volume of the non-uniform mass of fragments and the inability of a hot, non-asphalt-based binder applied to the top of the aggregate layer to penetrate and fill the much tighter mass.

FIG. 5 illustrates a test of an embodiment of the present invention in which a compacted layer of uniformly sized, compressible fragments of recycle tire rubber was placed in a PET tube and a hot, pigmented (gray) non-asphalt-based binder applied to the top of the layer of compressible fragments was able to fill and strongly bind the uniform mass of compressible fragments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in FIG. 1 , the structure and composition of the present invention for filling a wide crack, a wide joint, or other wide gap 2 in a pavement surface 4 are preferably formed by: (i) preparing the wide gap 2 in the pavement surface 4, e.g., by blowing dust and debris from the gap 2, routing, and/or sawing; (ii) preferably applying a base layer 6 of a non-asphalt and/or asphalt based binder to the bottom of the gap 2; (iii) forming a first compacted layer 8 of a compressible aggregate in the gap 2 on top of the base layer 6 of the non-asphalt-based and/or asphalt-based binder, the compressible aggregate being a mass of fragments of a compressible material which have a “uniform size”; (iv) applying a second layer 10 of a non-asphalt and/or asphalt based binder in the gap 2 on top of the compacted first layer 8 of the compressible aggregate so that at least a portion of the second layer 10 of non-asphalt-based and/or asphalt-based binder flows into voids in the compacted first layer 8 of the compressible aggregate to bind the first compacted layer 8 of the compressible aggregate together; (v) applying a subsequent compacted layer 12 of compressible aggregate in the gap 2 and then applying a subsequent layer 14 of a non-asphalt and/or asphalt based binder in the gap 2 on top of the subsequent compacted layer 12 of compressible aggregate so that at least a portion of the subsequent layer 14 of binder flows into voids in the subsequent compacted layer 12 of compressible aggregate to bind the subsequent compacted layer 12 of compressible aggregate together; and (vi) repeating step (v) if needed and as many times as needed to fill the wide gap 2 in the pavement surface 4.

As used herein, the terms “wide crack” or “wide joint” or “wide gap” refer to a crack, joint, or other gap 2 in a pavement surface 4 which has a width of greater than ¾ inch and more. More typically, the wide gap 2 will have a width of at least about 1 inch, or at least 1.5 inches, or at least about 2 inches. The width of the wide crack, joint, or other gap 2 which is filled and repaired using the method, structure, and composition of the present invention will preferably not be greater than about 18 inches, more preferably not greater than 12 inches, will more preferably be in the range of from about 2 inches to about 12 inches, and will more preferably be in the range of from about 2 inches to about 6 inches. Such cracks, joints, and other gaps in pavement surfaces will typically be from as short as about 2 inches to as much as about 30 feet or more in length and will typically have a depth 15 which ranges from as little as about 2 inches to as much as about 8 inches or more.

As used herein, the term “about” when used in reference to dimensional sizes means ±10%.

The compressible aggregate used in the method, structure, and composition of the present invention can be any mass of fragments which (1) are of uniform size, (2) are compressible, (3) provide structural stability and strength, (4) are compatible with the non-asphalt-based and/or asphalt-based binder such that the binder will strongly adhere to the compressible fragments and bind the repair together as a cohesive unit, and (5) give the inventive repair structure sufficient flexibility to withstand and accommodate the gap movements, expansions, and contractions which will occur due to the wide changes in the ambient temperatures to which the pavement substrate will be subjected throughout the year.

Examples of compressible recycled or waste aggregate materials suitable for use in the inventive method, structure, and composition include, but are not limited to, recycled tire rubber, EPDM rubber, nitrile rubber, natural or synthetic latex rubber, polyolefin elastomers, and fluoropolymer elastomers. The compressible aggregate material used in the present invention will preferably be recycled tire rubber which is shredded and screened to provide a mass of recycled tire rubber fragments of uniform size. It will also be understood that, although the compressible material used in forming each of the individual compacted layers of compressible aggregate in the inventive structure and composition will typically be the same, the compressible aggregate used in forming any given layer can alternatively be different from the compressible material used in forming any one or more of the remaining compacted layers of compressible aggregate.

As used herein and in the claims, the term “uniform size” means that the individual compressible fragments which make up each layer of the compressible aggregate mass formed in the inventive structure and composition will at least be close enough to each other in size that all of the fragments will be small enough to pass a screen mesh having 0.5 inch by 0.5 inch square openings but will be large enough that they will not pass an 8 mesh screen. Within this general “uniform size” range, examples of narrower size ranges of the mass of compressible aggregate fragments which are preferred for use in forming the various individual compacted layers of compressible aggregate in the inventive structure and composition include, but are not limited to: (i) a mass of compressible fragments which will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass a 4 mesh screen or (ii) a mass of compressible fragments which will pass a screen mesh having 0.375 inch by 0.375 inch square openings but will not pass an 4 mesh screen. Examples of other narrower size ranges which can be used include but are not limited to: (a) a mass of compressible fragments which will pass a 5 mesh screen but will not pass a 6 mesh screen or (b) a mass of compressible fragments which will pass a 6 mesh screen but will not pass an 8 mesh screen.

As commonly used in the art concerning granulated post-consumer and/or post-industrial rubber materials, all mesh sizes stated herein are standard U.S. mesh sizes. Generally speaking, in the present invention, as the mesh size gets larger and the average size of the fragments or particles gets smaller, the packing will become too tight to allow for adequate penetration and flow of the binder through the network of fragments.

It will also be understood that although the specific size range of the compressible fragments used in forming each of the individual compacted layers of compressible aggregate in the inventive structure and composition will typically be the same, the size range of any given layer of compressible fragments can alternatively be different from the specific size range of the mass of compressible fragments used in forming any one or more of the remaining compacted layers of compressible aggregate.

As noted above, the repair structure formed by the inventive method comprises alternating layers of (i) compacted compressible aggregate and (ii) non-asphalt and/or asphalt based binder. When filling a crack, joint, or other gap 2 using the inventive method, enough alternating layers of compacted aggregate and binder are preferably formed to fill the gap in question. This may require the formation of as little as one or as many as four or more layers 8, 12, 16, 20 of compacted aggregate. The layer(s) of bound aggregate will preferably fill the gap 2 to a level 24 which is not higher than, but is within at least about ½ inch below, the surface 4 of the pavement. The layer(s) of bound aggregate will more preferably fill the gap 2 to a level 24 which is about ¼ inch below the surface of the pavement.

By way of example, but not by way of limitation, each layer 8, 12, 16, 20 of compressible aggregate material can be compacted using normal tamping devices and tools used by those skilled in the art of roadway repairs. The depth of each compacted layer 8, 12, 16, 20 of compressible aggregate material will preferably be in the range of from about 1 to about 3 inches and will more preferably be in the range of from about 1 to about 2 inches.

The amount of the base layer 6 of the non-asphalt and/or asphalt based binder applied to the bottom of the crack, joint, or other gap 2 will preferably be an amount which is sufficient to fully cover the bottom of the void and adhere to any structures that form the sides or walls of the base of the repair. The base layer 6 of the binder will preferably be an amount which covers the bottom of the gap 2 in the pavement 4 to a thickness in the range of from about 0.5 inch to about 1 inch. The amount of each subsequent layer 10, 14, 18, 22 of binder which is applied to the top of a layer of compacted compressible aggregate material will preferably be an amount which is sufficient to fully coat and penetrate the layer of aggregate immediately below it. The amount of each subsequent layer 10, 14, 18, 22 of binder which is applied to the top of a layer of compacted compressible aggregate material will more preferably be about 0.5 to 1.0 inch.

The non-asphalt and/or asphalt based binder used in the inventive method, structure, and composition will preferably fill and strongly adhere to the compressible aggregate and will also strongly adhere to the walls of the crack, joint, or other gap 2 in the pavement surface 4. In most cases, the binder will preferably be hot-applied.

Asphalt-based binders can be used in the inventive method, structure, and composition for filling and repairing wide cracks, joints, and other gaps in asphalt pavements, but can also be used for repairing cement concrete pavements. Some asphaltic binders can also be pigmented, to some degree, to reduce the amount of color contrast between the asphaltic binder and an aged asphalt pavement or a cement concrete pavement to which the asphaltic binder is applied.

Non-asphalt-based binders can be used in the inventive method, structure, and composition for repairing wide gaps in asphalt pavements but will more preferably be used for filling and repairing wide cracks, joints, or other gaps in cement concrete pavements. Non-asphalt-based binders can be pigmented to generally any desired color, including the gray color of Portland cement concrete.

In forming the base layer 6 of binder material and in forming a series of bound layers 8, 12, 16, 20 of compressible aggregate on top of the base layer 6 to fill the wide crack, joint, or other gap 2 in the pavement surface 4, it will be understood that (a) the binder used to form the base layer 6 will typically be the same as but can alternatively be different from the binder used to form one or more of the bound layers of compressible aggregate, and (b) the binder used to form each individual bound layer of compressible aggregate will typically be the same as the other layers but cart alternatively be different from the binder or binders used to form one or more of the remaining bound layers of compressible aggregate.

In addition, it will be understood that (i) each layer of binder applied in the inventive method can be a layer of a non-asphalt-base binder, (ii) each layer of binder applied in the inventive method can be a layer of an asphalt-based binder, (iii) each layer of binder can be a combination asphalt and non-asphalt base binder, (iv) at least one layer of binder applied in the inventive method can be a non-asphalt-based binder while at least one other layer of binder applied in the inventive method is an asphalt-based binder or a combination asphalt and non-asphalt base binder, or (v) at least one layer of binder applied in the inventive method can be an asphalt-based binder while at least one other layer of binder applied in the inventive method is a non-asphalt-based binder or a combination asphalt and non-asphalt base binder.

In an alternative embodiment illustrated in FIG. 2 , the method, structure, and composition of the present invention involve, or are used for, filling a deep gap 30 in a pavement surface 32 wherein the gap 30 has (i) a depth 35 of at least 5.5 inches or more typically at least 6 inches or at least 6.5 inches, or at least 7 inches, or at least 7.5 inches, or at least 8 inches and (ii) a width of at least 1 inch, more typically at least 2 inches or at least 3 inches or at least 4 inches. By way of example, but not by way of limitation, the alternative method, structure, and composition of the present invention for filling deep gaps in pavement surfaces is well-suited for filling roadway trenches such as those produced by micro-trenching operations for burying lines and cables. Such trenches typically extend downwardly through the entire depth of the roadway pavement, which will commonly be in the range of from about 10 to about 16 inches.

In the alternative embodiment of the inventive method for filling deep gaps, the deep gap 30 is preferably first prepared, as needed, in generally the same manner as described above, e.g., by blowing dust and debris from the gap, routing, and/or sawing. However, although a base layer of a non-asphalt and/or an asphalt based binder can be applied to the bottom of the gap 30; the application of a base layer will typically not be needed in the alternative method for filling deep gaps and therefore will preferably not be used.

The alternative embodiment of the inventive method for filling a deep gap 30 preferably comprises the steps of: (a) forming only a single layer 34 of a compressible aggregate in the deep gap 30, the single layer 34 of the compressible aggregate being a layer of compressible fragments of uniform size (i.e., a mass of compressible fragments within a size range wherein the largest fragments will at least pass a screen mesh having openings which are 0.5 inch by 0.5 inch square openings or smaller, but the smallest fragments will not pass an 8 mesh (standard U.S. mesh) screen); (b) preferably compacting the single layer 34 of compressible aggregate, in the same manner as described above, sufficiently to at least prevent bridging, and then (c) applying an amount of a binder 36 on top of the single layer 34 of the compressible aggregate so that at least a portion of the binder 36 applied on top of the single layer 34 of the compressible aggregate flows into the voids in only an upper portion 38 of the single layer 34 of the compressible aggregate to bind the upper portion 38 of the single layer of the compressible aggregate together and to leave a lower portion 40 of the single layer 34 of the compressible aggregate unbound. The binder 36 applied on top of the single layer 34 of the compressible aggregate in step (b) can be a non-asphalt and/or an asphalt based binder.

As noted above, the single layer 34 the of compressible aggregate used in the alternative embodiment of the inventive method, structure, and composition will preferably be placed directly on the bottom 42 of the deep gap 30 without any base layer of binder material being first applied to the bottom 42 of the gap 30.

In the alternative method, structure, and composition for filling the deep gap 30, the depth 42 of the bound upper portion 38 of the single layer 34 of the compressible aggregate will preferably be equal to or less than the depth 44 of the unbound lower portion 40 of the single layer 34 of the compressible aggregate and will more preferably be less than the depth 44 of the unbound lower portion 40 of the single layer 34 of the compressible aggregate.

Typically, the depth 44 of the unbound lower portion 40 of the single layer 34 of compressible aggregate will be in the range of from about 4 to about 14 inches, or more, and the depth 42 of the bound upper portion 38 will be in the range of from about 1 to about 5 inches. More typically, the depth 44 of the unbound lower portion 40 of the single layer 34 of compressible aggregate will be in the range of from about 5 to about 14 inches or from about 6 to about 13 inches or from about 7 to about 12 inches or from about 8 to about 12 inches, and the depth 42 of the bound upper portion 38 will be in the range of from about 2 to about 5 inches, or from about 2 to about 4 inches, or from about 3 to about 4 inches.

The alternative method, structure, and composition for filling a deep gap 30 in a pavement surface 32 are particularly well suited for use in deep joints, cracks, or other gaps wherein the side walls of the gap 30 are reasonably intact so that the lower portion 40 of the single layer 34 of compressible aggregate will be retained in the gap 30 without being bound together.

The combination of the single layer 34 of compressible aggregate and the binder 36 applied to the upper portion 38 thereof will preferably fill the deep gap 30 to a level 46 which is not higher than, but is at or above a level which is about ½ inch below, the surface 32 of the pavement. The combination of the single layer 34 of compressible aggregate and the binder 36 applied to the upper portion 38 thereof will more preferably fill the deep gap 30 to a level 46 which is about ¼ inch below the surface 32 of the pavement.

By way of example, but not by way of limitation, hot-applied non-asphalt-based binders suitable for use in each embodiment of the inventive method, structure, and composition can be formed using a non-asphaltic base blend which comprises: (i) at least one processing oil, (ii) at least one epoxidized ester of a vegetable oil and/or at least one other plasticizing material, and (iii) one or more non-asphaltic resinous base materials (preferably a polar material) or other non-asphaltic rosin ester materials.

The total amount of the one or more non-asphaltic resinous components or other non-asphaltic rosin ester materials used in the base blend will preferably be an amount which is equivalent to at least 10% by weight, or at least 15% by weight, or at least 20% by weight, or at least 25% by weight, or at least 30% by weight, or at least 35% by weight, or at least 40% by weight, of the total final weight of the binder composition.

One group of resinous base materials that bear or can bear functional groups that are highly polar in nature and capable of forming hydrogen bonds, and which provide high adhesion and bonding strength for concrete substrates or substrates formed of Portland cement or mortars containing Portland cement or similar minerals, are rosin esters. Rosin esters commonly comprise amorphous, esterified mixtures of low molecular weight resins produced from the pulping or processing of wood. Free carboxylic acid groups present in the rosin material are esterified using hydroxyl-containing compounds. The esterified rosin material bears chemical functionality that is polar in nature and can undergo hydrogen bonding interactions with substrates, such as concrete pavements, that are also polar in nature.

The rosin ester material used in the non-asphalt-based binder can comprise a single rosin ester or a combination of two or more rosin esters. Rosin ester materials will typically have softening points of greater than 50° C. and needle penetration values of near 0 dmm at 25° C. The rosin ester material will preferably have (a) a softening point in the range of from about 80° C. to about 120° C., more preferably from about 95° C. to about 110° C., and (b) an acid number of less than 20 mg/g and more preferably less than 15 mg/g.

To facilitate the pigmenting processes, the rosin ester material will preferably be relatively translucent or have a lighter color. For pigmenting purposes, the Gardner Color of the rosin ester material will preferably be less than 10.0 and will more preferably be less than 7.0.

Examples of rosin ester materials suitable for use in the non-asphalt-based binder include, but are not limited to, pine-based pentaerythritol ester resins, pine-based glycerol ester resins, and pine-based ester resins esterified using other readily available glycols bearing hydroxyl functionality.

The rosin ester material will preferably be or comprise a pine-based pentaerythritol ester resin. An example of a commercially available pine-based pentaerythritol ester resin is WESTREZ Rosin Ester 5101 produced by Ingevity of Charleston, SC.

In addition or as an alternative to such rosin ester materials, examples of other types of polar, non-asphalt base resins suitable for use in the base blend of the non-asphalt-based binder include, but are not limited to: polyurethane resins such as those derived from the reaction of one or more isocyanate compounds with a flexible chain extender, preferably a polyether-ester or polyether-amide; epoxy resins such as epoxy resins based on the diglycidyl ether of Bisphenol-A (DGEBA) and DGEBA that is modified with flexible diamines or flexible diols to improve impact toughness; and silane-based resins that contain silanol functionality, such as polysiloxanes that are commercially available and used in the production of silicone elastomers.

The processing oil used in forming the non-asphaltic base blend will preferably comprise one or more aromatic, naphthenic, paraffinic, and/or vegetable oils. The processing oil will preferably (a) be relatively translucent or have a lighter color, which further facilitates the pigmenting process, (b) be effective for blending with the rosin ester material to produce a softening point of the base blend in the range of from about 40° to about 70° C. and a needle penetration value of the base blend in the range of from about 20 to about 80 dmm at 25° C., and (c) have an aromatic content of at least 40% by weight, or at least 45%, 50%, 55%, 60%, 65% or 70% by weight, based upon the total weight of the processing oil.

Examples of commercially available processing oils which are well suited for blending with pine-based pentaerythritol resins and other rosin materials are SUNDEX 165 (an aromatic processing oil having a molecular weight of 588 and an aromatic content of 55% by weight based upon the total weight of the SUNDEX 165) and HYDROLENE LPH. SUNDEX 165 and HYDROLENE LPH are available from HollyFrontier Lubricants and Specialty Products of Tulsa, OK.

The amount of processing oil used in the base blend will preferably be at least 2% and will more preferably be in the range of from 5% to 30% by weight based on the total final weight of the binder composition.

The one or more plasticizing materials used in forming the non-asphaltic base blend will preferably comprise one or more epoxidized esters of vegetable oils and will also preferably be relatively translucent or have a lighter color. Examples of epoxidized esters of vegetable oils suitable for use in forming the base blend used in the binder composition include, but are not limited to, epoxidized esters of soybean oil, corn oil, tall oil, and sunflower oil. The epoxidized ester of vegetable oil will preferably be an epoxidized ester of soybean oil and will most preferably be an epoxy functionalized methyl ester of soybean oil. Examples of other suitable epoxidized esters of soybean oil include, but are not limited to, benzyl, propyl, and ethyl esters of soybean oil.

Examples of other types of plasticizers suitable for use in the non-asphaltic base blend include, but are not limited to, esters derived from vegetable oil fatty acids, esters and diesters derived from the esterification of fatty alcohols and carboxylic acids, or from the esterification of alcohols with fatty acids, hydrogenated and non-hydrogenated aromatic oils and related petroleum distillates, hydrogenated and non-hydrogenated naphthenic oils and related petroleum distillates, and paraffinic oils and distillates.

The amount of plasticizer used in the base blend will preferably be at least 1% and will more preferably be in the range of from 0.5% to 6% by weight based on the total final weight of the binder composition.

In addition to the non-asphaltic base blend, the non-asphaltic binders will also preferably include one or more elastomeric polymer materials which modify the pigmented base blend to provide enhanced mechanical properties. Examples of elastomeric polymer materials suitable for use in the non-asphaltic binders include, but are not limited to: styrene block polymers such as radial and/or linear styrene butadiene styrene (SBS) block copolymers, styrene butadiene copolymers, styrene isoprene copolymers, and styrene isoprene styrene (SIS) block copolymers; ethylene vinyl acetate (EVA); polymers such as ethylene-propylene-diene monomer rubber (EPDM) formed by the copolymerization of ethylene and propylene with suitable monomers to disrupt crystallinity; acrylic copolymers and terpolymers such as butyl acrylate and glycidyl methacrylate, which are derived from copolymerization of ethylene with acrylic monomers; and combinations thereof. The one or more elastomeric polymer materials will preferably comprise an SBS polymer and/or an SIS polymer and will more preferably comprise a radial SBS polymer.

If present, the amount of elastomeric polymer material used in the binder will typically be at least 3% and will more typically be in the range of from 6% to 12% by weight of the total final weight of the non-asphaltic binder composition.

The non-asphalt-based binders can also include mineral or other inorganic fillers which reduce the cost and/or improve one or more of the high temperature performance characteristics of the binder composition. Examples of suitable inorganic filler materials include, but are not limited to, titanium dioxide, ferric oxide, talc, calcium carbonate, fly ash, silica, alumina-based inorganic materials, and combinations thereof. If present, the amount of inorganic filler used in the binder will typically be at least 2% or at least 3% or at least 4% or at least 5% or at least 6% by weight of the total final weight of the binder composition and will more typically be in the range of from 6.5% to 24% by weight of the total final weight of the non-asphaltic binder composition.

For pigmentation purposes, the non-asphaltic binders can also comprise (a) one or more color-neutralizing materials (one of said one or more materials preferably being titanium dioxide) which assist(s) in significantly or entirely neutralizing a non-white shade or color of the non-asphaltic base blend and (b) one or more pigment materials which impart a desired end color to the color-neutralized base blend.

Although other procedures can be used and the order or manner of adding the individual components can be changed, the non-asphaltic binders will preferably be prepared by first combining the components of the base blend. The base blend is preferably prepared by: (i) heating the processing oil to a blending temperature in the range of from about 300° F. to about 350° F. (more preferably from about 320° to about 330° F.) while applying low shear agitation or mixing; (ii) adding the one or more plasticizers to the heated processing oil with low shear agitation or mixing and with continued heating as required to maintain the blending temperature; (iii) then adding the rosin ester material and/or other non-asphaltic resin material with continued low shear agitation or mixing and with continued heating to maintain the blending temperature; and then (iv) continuing to agitate or mix the resulting blend at the blending temperature until the rosin ester and/or other resin material is/are melted and fully incorporated in the processing oil.

The total amount of the rosin ester material and/or other resin material added to the base blend will preferably be at least 30% by weight or will be at least 35% or at least 40% or at least 41% or at least 42% or at least 43% or at least 44% or at least 45% by weight, based upon the total final weight of the non-asphalt-based binder composition. The total amount of the rosin ester material and/or other resin material added to the base blend will preferably be in the range of from 35% to 65% by weight based upon the total final weight of the non-asphaltic binder composition.

Because of the materials used in forming the base blend, the base blend will typically have a non-white shade or color which will range from light yellow to light or medium brown. For pigmentation purposes, the non-white shade or color of the base blend can be at least partially neutralized, more preferably substantially or entirely neutralized, prior to pigmenting the non-asphalt-based binder composition to its desired final color. The non-white shade or color of the base blend will preferably be significantly or entirely neutralized by: (1) maintaining the blending temperature of the base blend while adding titanium dioxide thereto with mixing and (2) continuing to maintain the blending temperature of the base blend while adding any additional color-neutralizing materials thereto with mixing. Although high shear and/or high-speed mixing may be needed in some circumstances, maintaining the temperature of the base blend in the range of from 300° F. to 350° F. will typically allow low speed and/or low shear mixing to be used for incorporating and dispersing the TiO₂ and any additional color-neutralizing materials.

When needed for incorporating the titanium dioxide and/or other color-neutralizing materials, high shear mixing can more effectively overcome the forces of attraction between adjacent TiO₂ or other particles, thereby more readily breaking up and dispersing TiO₂ or other agglomerates into separate particles.

As used herein, the term “high-speed and/or high shear” mean the use of mixing equipment that provides a high rate of rotation of typically in excess of 1000 rotations per minute (rpm) and more typically in excess of 2000 rpm. The high shear mixing also forces the material through a small or narrow gap, thus imparting relatively high levels of shear stress to the material and helping to break apart and disperse agglomerations.

Examples of devices and systems suitable for high speed and/or high shear mixing include, but are not limited to, SiIverson® laboratory mixers with high shear milling heads, rotor-stator mills, and Cowles mixers.

As used herein, the term “low speed and/or low shear” means a speed of less than 1000 rpm, more preferably less than 750 rpm, and more preferably 500 rpm or less. Examples of suitable low speed mixing devices or systems include, but are not limited to, low speed paddle mixers or agitators.

The titanium dioxide used in the non-asphalt-based binder for pigmentation purposes acts as a whitener for neutralizing the yellow or brownish color of the base blend and also serves as a filler material. The TiO₂ can be in any crystalline form, including rutile or anatase titanium dioxide, and will preferably be rutile titanium dioxide. The amount of titanium dioxide added to the base blend in the color-neutralization step will preferably be in the range of from about 3% to about 20% by weight, more preferably from about 5% to about 15% by weight, based upon the total final weight of the pigmented binder composition after the titanium dioxide, any additional color-neutralizing materials, the one or more pigment materials, and the one or more elastomeric polymer materials, as well as any other inorganic filler, have been added to the base blend.

Examples of additional color-neutralizing materials which can be added to the non-asphaltic base blend in the color-neutralizing step can include, but are not limited to, calcium carbonate, blue pigments, and combinations thereof.

When used as an additional color neutralizing agent, calcium carbonate will preferably be added to the base blend in an amount in the range of from about 1% to about 20% by weight, more preferably from about 3% to 15% by weight, based upon the total final weight of the pigmented non-asphalt-based binder composition.

In many cases, even after the addition of titanium dioxide and calcium carbonate to the base blend, a slight yellow color will remain. As an additional color neutralizing agent for neutralizing the remaining the yellow color, a blue pigment can also be added to the base blend in an amount in the range of from about 0.1% to about 5% by weight, more preferably from about 0.5% to about 2% by weight, based upon the total final weight of the pigmented non-asphaltic binder composition.

The at least partially color-neutralized base blend can be pigmented to achieve generally any non-white shade or color desired for the final pigmented binder composition. In accordance with the inventive method, the at least partially color-neutralized non-asphaltic base blend will preferably be pigmented by (1) continuing to maintain the neutralized base blend at the blending temperature while (2) adding one or more pigment materials to the neutralized base blend with mixing. Although high shear and/or high-speed mixing may be needed in some circumstances, maintaining the temperature of the color-neutralized base blend in the range of from 300° F. to 350° F. will typically allow low speed and/or low shear mixing to be used for incorporating and dispersing the one or more pigment materials.

The one or more pigment materials can be generally any heat-stable pigment(s). Examples of suitable pigment materials to achieve desired end colors include, but are not limited to, gray pigments such as Gilsonite and red pigments such as iron oxides and hydrates of iron oxide salts.

The one or more pigment materials can be added to the at least partially neutralized non-asphaltic base blend as needed to achieve the desired end color. The one or more pigment materials will typically be added in an amount in the range of from 0.1% to about 6% by weight, more typically from about 0.3% to about 4% by weight, based upon the total final weight of the pigmented binder composition after the titanium dioxide, any additional color-neutralizing materials, the one or more pigment materials, and the one or more elastomeric polymer materials have been added to the base blend.

As will be understood by those skilled in the art, pigments sometimes include carrier materials. Consequently, as used herein, a weight amount or percentage amount or concentration stated for any color-neutralizing material or pigment material includes any carrier material which is contained in the color-neutralizing or pigment material.

The use of Gilsonite powder in the pigmenting step has shown to be particularly effective in achieving a gray tone similar or identical to Portland cement concrete.

If the non-asphaltic binder composition is pigmented, the one or more elastomeric polymer materials used in the binder composition will preferably be added after the pigmenting steps.

The one or more elastomeric polymer materials are preferably added to the pigmented non-asphaltic base blend by (1) increasing the temperature of the pigmented base blend to a temperature in the range of from about 350° F. to about 385° F., (2) adding the one or more elastomeric polymer materials, preferably with low shear agitation or mixing, while maintaining a temperature of from about 350° F. to about 385° F., and (3) continuing the low shear agitation or mixing at a temperature of from about 350° F. to about 385° F. until complete dissolution of the polymer material(s) is achieved (typically at least 6 hours). The one or more elastomeric polymer materials will preferably be added to the pigmented base blend in an amount in the range of from about 2% to about 20% by weight, more preferably from about 3% to about 15% by weight, based upon the total weight of the final non-asphaltic binder composition.

As an example of another type of non-asphalt-based binder which can be used as an alternative to the non-asphalt-based binders and methods of forming the binders as just described, the non-asphalt-based binder used in each embodiment of the inventive method, structure, and composition can be a polyurethane resin binder formed, e.g., by combining two (binary) reactants for the polyurethane resin prior to or during application and then, after application, allowing the polyurethane resin to cure. By way of example, but not by way of limitation, as will be understood by those in the art, one of the binary reactants used for forming the polyurethane resin will preferably be a polyurethane prepolymer, preferably a hydroxyl functionalized polyester or polyether, and the other will preferably be a curing agent, preferably a multifunctional isocyanate. One such binary system comprised of part “A” and part “B” reactants is available from Roklin Systems Inc. of Ventura, CA. Polyurethane resin binders of this type can typically be formed and applied at ambient temperature.

By way of example, but not by way of limitation, hot-applied asphalt-based binders suitable for use in each embodiment of the inventive method, structure, and composition can comprise: (a) a total percent by weight of asphalt (% Asphalt) which is preferably not less than 50% by weight of the total weight of the asphaltic binder composition; (b) a total percent by weight of one or more plasticizers of the same type as described above (% Plasticizer) which is preferably not less than 2% by weight of the total weight of the asphaltic binder composition; (c) a total percent by weight of one or more polymers of the same type as described above (% Polymer) which is preferably not less than 4% by weight of the total weight of the asphaltic binder composition; and (d) optionally an inorganic filler (preferably titanium dioxide and/or ferric oxide) and/or crumb rubber in an amount in the range of from 0% to 15% by weight based upon the total weight of the asphaltic binder composition.

In order to provide an improved softening point, improved resilience, and good ductility, the asphalt-based binder composition will also preferably have an Effective Polymer Concentration (EPC) value of not less than 7.0, wherein the EPC value of the asphalt-based binder is defined as:

EPC=(% Polymer÷(% Polymer+% Asphalt+% Plasticizer))×100.

In addition, in order to maintain or improve the ductility of the asphaltic binder and provide a desirably lower viscosity, the ratio of the total percent by weight of the one or more plasticizers (% Plasticizer) to the total percent by weight of the one or more polymers (% Polymer) will preferably be in the range of from 0.4:1 to 0.6:1.

The base asphalt used in the asphalt-based binder composition can generally be any viscosity, penetration, or Performance Graded (PG) asphalt using the Performance Grading AASHTO asphalt specification. Examples of suitable base asphalt materials include, but are not limited to, asphalts graded as PG 64-22, PG 58-28, PG 67-22, PG 52-34, AC-5, AC-10, AC-20, AC-30, 40-60 pen, 60-70 pen, 85-100 pen, or 120-150 pen, or combinations thereof.

Examples of inorganic fillers suitable for use in the asphalt-based binder include, but are not limited to, titanium dioxide, ferric oxide, talc, calcium carbonate, fly ash, silica, alumina-based inorganic materials, and combinations thereof. If an inorganic filler is included in the asphalt-based binder, the inorganic filler will preferably be limited to titanium dioxide and/or ferric oxide.

If present in the asphalt-based binder, the titanium dioxide filler will preferably be a typical rutile TiO₂ having an alumina or silica coating for improved dispersibility and oil absorption. Rutile titanium dioxide particles of the type treated with an organic coating to further promote dispersion in oil-based media are also preferred. Alternatively, or in addition, if a ferric oxide filler is used in the asphalt-based binder, the ferric oxide filler will preferably be a particulate ferric oxide having a fine particle size of 5 microns or less, and more preferably 1 micron or less, which is well suited for effective dispersion and pigmenting effect.

Also, if present in the asphalt-based binder, the crumb rubber used will preferably have a particle size of less than 600 micron and more preferably less than 500 micron.

As another alternative, the binder used in each embodiment of the inventive method, structure, and composition can be a hot-applied asphalt-based binder composition of any type described herein but with a portion of the asphalt-base material being replaced with one or more non-asphaltic resinous base materials of any type described above. The amount of the asphalt-base material which is replaced with the non-asphaltic resinous base material(s) will preferably be such that the weight ratio of the of the asphalt-base material to the non-asphaltic resinous base material(s) used in the binder composition will be in the range of from about 40:60 to about 80:20 (i.e., the term “about” meaning±10% of the weight amount of the asphalt-base material being replaced by the non-asphaltic resinous base material(s)). The weight ratio of the asphalt-base material to the non-asphaltic resinous base material(s) will more preferably be in the range of from about 50:50 to about 70:30 and will more preferably be about 60:40.

The one or more non-asphaltic resinous base materials used for replacing a portion of the asphalt-base material in the asphalt-based binder will preferably be one or more rosin esters of the type described hereinabove. Examples of preferred rosin esters include pine-based pentaerythritol ester resins, pine-based glycerol ester resins, and pine-based ester resins esterified using other readily available glycols bearing hydroxyl functionality. The one or more rosin ester materials will more preferably be or comprise a pine-based pentaerythritol ester resin.

The replacement of a portion of the asphalt-base material with one or more non-asphaltic resinous base material(s) desirably reduces the viscosity of the asphalt-based binder and enables the binder composition to flow into and permeate the compressible aggregate material at a lower temperature. For example, at an asphalt to non-asphalt ratio of 60:40 by weight, the binder can be applied to the compressible aggregate at a temperature of from 275° to 325° F., while still retaining the shear strength and other important properties of asphalt after cooling. A further reduction in viscosity can be achieved by including from 1% to 10% by weight, more preferably 2% to 5% based upon the total final weight of the binder composition, of one or more epoxidized esters of vegetable oil and/or other plasticizers.

The following example is provided solely for purposes of illustration, not limitation.

EXAMPLE

We have discovered that a very effective way to visually evaluate the void volume of a mass of aggregate fragments, and the degree to which a hot binder material applied to the top of aggregate is able to fill the void volume of the aggregate mass, is to place a compacted layer of the aggregate material in a transparent tube formed from a transparency film of PET. PET is a unique polymer having a melting point in excess of 450° F. Consequently, PET will maintain its structural rigidity, i.e., will not melt, when contacted with a hot-applied binder material at a typical application temperature of between 350° F. and 400° F. Moreover, a PET transparency film will turn black in the areas contacted by the hot binder, in much the same manner that latent images are formed on PET transparencies during copying by exposing the transparencies to heat. From the change in color which is produced in the PET transparency at each location where the transparency is contacted by the hot-applied binder, it can clearly be seen where and the degree to which the binder is able to flow (or not flow) through the aggregate mass and fill the void spaces therein.

For purposes of comparison, FIG. 3 is an illustration showing a compacted layer of an incompressible, crushed rock aggregate material of uniform size (i.e., a uniform crushed rock aggregate as would be used in constructing a macadam pavement) which was placed in a transparent PET tube. FIG. 3 also shows the flow into the void spaces of the uniform rock aggregate of a hot non-asphalt-based binder which was applied to the top of the aggregate layer. The hot-applied non-asphalt-based binder was pigmented to provide a gray color corresponding to Portland cement concrete.

As illustrated in FIG. 3 , the hot-applied binder was able to penetrate throughout and substantially fill the void structure of the uniform incompressible aggregate material to form a strong, rigid, load-bearing structure. However, due to the incompressibility of the crushed rock aggregate, the bound structure of FIG. 3 is not suitable for use in repairing or filling wide cracks, joints, or other gaps in cement concrete pavements or even blacktop pavements.

Also for comparison purposes, FIG. 4 is an illustration showing a compacted layer of an incompressible, crushed rock aggregate which was placed in a PET tube. The layer of aggregate shown in FIG. 4 , which was not of uniform size, contained a significant quantity of unscreened smaller fragments which filled the internal voids between the larger fragments, thus forming a much tighter structure such that a hot, non-asphalt-based binder applied to the top of aggregate layer was substantially unable to penetrate the tighter mass. Consequently, the resulting structure was dimensionally unstable, weak, and non-load bearing.

FIG. 5 illustrates the present invention in which a compacted layer of uniformly sized, compressible fragments of recycle tire rubber was placed in a PET tube and a hot, pigmented (gray), non-asphalt-based binder was applied to the top of the layer of compressible fragments. As seen in FIG. 5 , the hot-applied binder was able to penetrate throughout and substantially fill the more open void structure of the compacted, uniformly sized, compressible aggregate material to form a strong, rigid, load-bearing structure which was well suited for use in filling and repairing wide cracks, joints, or other gaps in concrete cement pavements and asphaltic pavements.

Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those in the art. Such changes and modifications are encompassed within the invention as defined in the claims. 

1. A method of filling a gap in a pavement surface comprising steps of: a) forming a layer of a compressible aggregate in the gap in the pavement surface, the layer of the compressible aggregate being a layer of compressible fragments of uniform size wherein the compressible fragments will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh screen and b) applying a binder on a top of the layer of the compressible aggregate which flows downwardly into voids in the layer of the compressible aggregate.
 2. The method of claim 1 wherein the binder comprises a non-asphalt-based binder.
 3. The method of claim 2 further comprising the non-asphalt-based binder including a non-asphaltic base blend which comprises (i) one or more non-asphaltic resinous base materials or non-asphaltic rosin ester materials, (ii) at least one processing oil, and (iii) at least one epoxidized ester of a vegetable oil and/or at least one other plasticizer.
 4. The method of claim 2 wherein the non-asphalt-based binder comprises a pine-based pentaerythritol ester resin.
 5. The method of claim 2 wherein the non-asphalt-based binder comprises a polyurethane resin.
 6. The method of claim 5 further comprising combining binary reactants for forming the polyurethane resin prior to or during step (b) and then, after step (b), allowing the polyurethane resin to cure.
 7. The method of claim 1 wherein the binder comprises asphalt and one or more non-asphaltic resinous base materials.
 8. The method of claim 1 wherein the binder comprises said asphalt and a pine-based pentaerythritol ester resin.
 9. The method of claim 1 further comprising the compressible aggregate comprising recycled tire rubber, EPDM rubber, nitrile rubber, natural or synthetic latex rubber, a polyolefin elastomer, or a fluoropolymer elastomer.
 10. The method of claim 1 further comprising the compressible aggregate being recycled tire rubber.
 11. The method of claim 1 further comprising a step, prior to step (a), of forming a base layer by applying a binder to a bottom of the gap in the pavement surface, the binder used in forming the base layer being the same as or different from the binder used in step (b).
 12. The method of claim 1 further comprising steps, after step (b), of: c) forming, in the gap in the pavement surface on the layer of the compressible aggregate formed in step (a), a second layer of a compressible aggregate which is the same as or different from the compressible aggregate used in step (a), the second layer of the compressible aggregate formed in step (c) being a layer of compressible fragments of uniform size which will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh screen and d) applying a binder on a top of the second layer of the compressible aggregate formed in step (c) which flows downwardly into voids in the second layer of the compressible aggregate formed in step (c), the binder used in step (d) being the same as or different from the binder used in step (b).
 13. The method of claim 12 further comprising the gap in the pavement surface having a width of at least about 2 inches.
 14. The method of claim 12 further comprising: the layer of the compressible aggregate formed in step (a) having an entire depth of from about 1 to about 3 inches; the binder applied in step (b) being applied in an amount which binds the entire depth of the layer of the compressible aggregate formed in step (a); the second layer of the compressible aggregate formed in step (c) having an entire depth of from about 1 to about 3 inches; and the binder applied in step (d) being applied in an amount which binds the entire depth of the second layer of the compressible aggregate formed in step (c).
 15. The method of claim 1 further comprising the binder being applied in step (b) in an amount which flows downwardly into and binds only an upper portion of the layer of the compressible aggregate and leaves a lower portion of the layer of the compressible aggregate below the upper portion unbound.
 16. The method of claim 15 further comprising the upper portion of the layer of the compressible aggregate having a depth which is less than a depth of the lower portion of the layer of the compressible aggregate.
 17. The method of claim 16 further comprising: the gap in the pavement surface having a depth of at least 5.5 inches and the layer of the compressible aggregate and the binder applied thereto together filling the gap in the pavement surface to a level which is about ½ inch below the pavement surface or higher.
 18. The method of claim 16 further comprising: the depth of the upper portion of the layer of the compressible aggregate being in a range of from about 1 to about 5 inches and the depth of the lower portion of the layer of the compressible aggregate being in a range of from about 4 to about 14 inches.
 19. The method of claim 18 further comprising the depth of the lower portion of the layer of the compressible aggregate being in a range of from about 6 to about 13 inches.
 20. The method of claim 15 further comprising the layer of the compressible aggregate being a layer of recycled tire rubber
 21. A method of filling a gap in a pavement surface comprising: sequentially constructing in the gap in the pavement surface a series of bound aggregate layers; each of the bound aggregate layers being constructed of a layer of a compressible aggregate and a binder which is applied on top of the layer of the compressible aggregate and flows downwardly into voids in the layer of the compressible aggregate and binds the layer of the compressible aggregate; and the layer of the compressible aggregate of each of the bound aggregate layers being a layer of compressible fragments of uniform size wherein the compressible fragments will pass a screen mesh having 0.5 inch by 0.5 inch square openings but will not pass an 8 mesh screen.
 22. The method of claim 21 further comprising, prior to constructing the series of bound aggregate layers in the gap of the pavement surface, applying a base layer of a binder to a bottom of the gap in the pavement surface.
 23. The method of claim 21 further comprising the layer of the compressible aggregate of each of the bound aggregate layers being a layer of recycled tire rubber. 